All flux should be added upon firing; if the weapon cannot fire, it should not add any flux. It should only just not fire; no flux should be added. For energy weapons, the flux added upon firing can be used in the damage calculations for the power of the projectile at that time for the overcharge bonus.
There is a seriously problem with high charge-up flux generating weapons (ie, plasma cannon), where both players (because this is NOT EASILY APPARENT; sometimes it can be off by just a smidgeon and you get doomed anyways) and the autofire AI (which should know better!) do not know if there is enough flux for the weapon to actually fire, and so fire it anyways, and the weapon will charge up, generating flux, but when it reaches the max flux level, it just stops, leaving the ship with a massive amount of flux (and thus very vulnerable to overload), and utterly nothing to show for it. Its ASTONISHINGLY ANNOYING. With all caps. And bolded, underlined font. With the formatting lampshaded. With the lampshading becoming increasingly meta. That is just how annoying it is.
